Rotary gas-engine.



P. M. FREER.

RQTARY GAS ENGINE.

APPLICATION FILED Nov.6.1912. RENEwED ocT. 1911911.

Patented July 16, 1918,

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P. TV1i FREER.

v ROTARY GAS ENGINE.

APPLICATION man Nov. s, 1912. HENEWED oc. 19,1911.

Pafentsd July 16, 19H3.

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P. M. FREER.

ROTARY GAS ENGINE.

APPLICATION miv Nov. e, 1912. nENEwED ocr. 19. 1911.

1 ,272,79 1 v Patented J uly 16, 1918.

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PHELPS M. FREER, OF DETROIT, MICHIGAN.

ROTARY GAS-ENGINE.

Application filed November 6, 1912, Serial No. 729,720. Renewed October 19, 1917.

To all whom z' may concern.'

Be it known that I, PHnLrs M. FREER, a citizen of the United States, residing at Detroit, `I/Vayne county, Michigan, have invented certain new and useful Improvements in Rotary Gas-Engines, of which the following is a specification, which, together with the accompanying drawings, forming a part thereof, will enable those skilled in the art to which the invention pertains to make and use the same.

The invention relates to rotary gas engines of that type in which a rotatable member, or rotor having a radially disposed cylinder or plurality of cylinders is mounte and revolves upon its own bearings within a fixed annular casing or stator, provided with suitable inlet and exhaust ports and having other bearings in which is independently mounted a shaft with its crank or cranks pitman-.connected to the piston or pistons and driven thereby. in a direction of rotation opposite to that of the rotor.

The main object of this invention is to so perfect the general construction of the engine and its details and the relative disposition of the parts, that it will run smoothly and freely, and even at its highest speeds elfect such complete combustion of its ygas charges that their full power value will be attained with lresulting high efliciency of the engine. Generally itsobjects areV to minimize the number yof .working parts of the engine, such as movable valvesfor the inlet and exhaust ports, to simplify and cheapen the production of this engine as compared to others of equal powers; and to secure the advantages of both the two. cycle and the four cycle types of gasv engine, in that for each revolution of the rotor the explosive charge in its cylinder or in each of its cylinders is fired, as in the two cycle type, and that during each such revolution each piston will make two complete reciprocations whereby the. operations of charging, firing and scavenging the cylinders is similar to those of the four-cycle type. In effecting these, and such other objects as may be mentioned later, the invention consists of such improvements in the details and assembly of the parts as will hereinafter be specifically pointed out in detail. and embraced in the claims.

The accompanying drawings show the improvements of this invention informs now .considered moet desirable bei it is Het .in-

Specieation of Letters Patent.

Patented July 16, 1918.

Serial No. 197,497.

' tended to confine it to the precise forms and arrangements shown for many changes might be made therein without material departure from the spirit of the invention as set forth in the claims following this specification.

Figure 1 is a vertical sectional elevation of a rotary gas engine embodying the features of this invention, the section being taken on the irregular line specifically indicated by arrows 1, 1 of Fig. 2 and the line 1, 1 of Fig. 3.

Fig. 2 is a vertical transverse section of the same on the line 2, 2 of Fig. 1.

Fig. 3 is a vertical transverse section, on

the lines 3, 3 ofFigs. 1 and 1, of the casing or stator member only.

Fig. 4 is a face or side view as seen from the direction of arrow 4 on Fig. 3, of one half of the stator member with its rear plate or cover removed.

Fig. 5 is an outside elevation of the rear plate or cover of the stator as seen from the `direction of arrows 5 on Figs. 2 and 3.

Fig. 6 is a horizontal section ou the line 6, 6 of Fig. 1, through the stator and rotor in their assembled relation, the crank shaft and piston being omitted.

Fig. 7 is a perspective view of a group of gearing which so connects the rotor to the crank shaft as to cause these membersto rotate in opposite directions.

Fig. 8 is a view on enlarged scale of a portion of the peripheral face of the rotor showing the cylinder-closing shoe and other adjacent features.

Fig. 9 is a section of the same on the line 9, 9 of Figs. 8 and 10.

Fig. 10 is a sectional elevation of the same on the lines 10, 10 of Figs. 8 and 9.

Fig 11 is a view similar to Fig. 10 illustrating a modification.

Figs. 12, 13 and 141 illustrate a modification of the outer end of a cylinder having its end closed by an integral cast cover or closure instead of by a separable shoe as shown in Figs. 8 to 11 inclusive; Fig. 12 being a transverse section on the line 12, 12 of Fig. 13; Fig. 13 a transverse section ofthe same on the lines 13, 13 of Figs. 12 and 14 and Fig. 141 a view of the peripheral face of the rim with firing slot leading to the cylinder which is shown by dotted lines.

Fig. 15 is a side elevation illustrating a modification of a rotor made in two separable parts, divided on the axial line and joined by boltsV or other suitable means. It further illustrates a modified construction comprising a metal band ,or tire suitably secured upon the peripheral face of the rotor.

Fig. 16 is a. transverse section of the same on the line 16, 16 of Fig. 15. The heat-radiation flanges of the cylinders are omitted from Figs. 12 to 16 inclusive as not being necessary'tothe specific features these figures are especially designed to illustrate. The fixed' casing or stator A of this invention comprises an annular metallic shell or cylinder a preferably of cast iron, and arranged about an axis which, preferably is horizontally disposed. The interior surface of this shell is smoothly bored and is continuousexcept for the elongated openings a and e2 of the inlet and exhaust ports respectively, the spark plug openings a3 and other minor openings for" lubrication, etc. The sides of the stator are pierced with numerous large apertures fas shown by Figs. 3, 4: and 5, for the passage of air drafts7 and one side A is made separable and secured by bolts or other suitable mcansf'V A water-j acket passage B is formed upon' the outer surface of the shell7 extending around'it from an inlet pipe to an offtale pipe b2, its continuity being broken by ay paiL tition wall between the openings forthe said tivo pipes. Shaft bearings c and c? are formed on the axisof the stator and concentric therewith are inwardly projecting annular flanges fl and cl2, of larger diameter, for the rotor bearings which are thus mounted independently7 of the shaft bearings. On the outer or rear face of the main member of the stator frame is formed a gear casing E provided with a separable cover EAV and having an outer shaft-bearing c3 and a pair of gear shaft bearings f3 and f4 opposed t0 similar bearings f and f2 in the casing to support gear counter shafts as will presently be explained. Both sides ofthe stator are solid Walled near the axis to form closures for the open ends of an oil-tight crankcase formed in the rotor, as will presently be explained, to prevent the oil from splashing out laterally, and the main member has an additional inwardly projecting dished flange z5 with an inturned, hooked edge a6 to Catch and restrain the radial or centrifugal flow ofthe oil at that side. Y

On the outer side of the other member A is formed an upright tubular air duct G leading upwardly from the bearing c2 and provided with flanges g which extend across duct from alternate sides, as shown Vand serve to baffle the direct rush of air through the duct and separate from it any particles ofv lubricant which it might, if uninipeded,

be able to carry out of the crank case.' This duct communicates with the interior ofthe stator casing through apertures 'lr/v. These features-'relate to a breather-or aspirator ,other duplicate" rafts'- vflanges ha nd parti ally System to relieve the closed crank casing of the rotor from undue vacuum or pressure of air will 'Pl'.elltly be explained. The stator is provided with feet or lugs a7 by means of which it maybe secured to a. suitable base. The inlet port a may be connectedtoa carbureter or other source of gas supply by the .pipe 1?, and the exhaust led away by suitable' piping'froiii' the v"rounded extension a8 ofthe Aegfgluiust port a?. Y f

A` rotatable in 'emb'er'orv rotor H, located within the stator` ,comprises a'flat' faced vrim ZL, freely Vfittfe'd'toy thevboie of the stator', Va closed central. `cranlr case L, a cylinder or plurality of cylinders I opening into the crank Acase and extending thence to the rim, and radial arms orspokes h2 connecting the crank case and rim at'lsuitable intervals between the cylinders. In the construction shown .by the drawings two cylinders are shown upon opposite sides'of the rotor but a greater or less number may be employed -asde ined, and ,to avoid consta-nt repetition of alt e rnative expressions of numbers itwill be ,iinderstood that'hereinafter mention of a single .part will apply' with equal yforce to all v The crank case of the rotor is" provided with yannular bearing y l[t4 which engage the stator bearing fianges d and cl2 and support the rotorI independently of the `shaft bearings. This entirely relieves theshaftand its bearings of the strains and thrusts of the oppositely. revolving rotor andA greatly reduces the bearing friction in the engine and the wear on the shaft and its bearings.

Thev main'p'ortion 0f the rotor may be a single integral casting asshown in Figs. 1, 2 andy 6 but where more than one cylinder is employed it is more convenient in the-assembling of'the Working parte, to divide itfinto txvo'or morey separable portionsas along the line H Figs, 15 and 416 and secure these parts together by bolts h5 or otherv suitable means. Such division is preferably vmade on a line crossing. the axis and through one of the arms or spokes between'the cylinders as shown in said figures.

The rotor is'preferably made of cast iron, because of its workable'nature, but this inetal has low tensile strength and is therefore wealrunder the strains of high centrifugal force. "'ln order to strengthen the rotor against such strains and also to reinforce the connections between them when the rotor is made in two' `or more parts a band or tire H2 of steel o r other suitable metal may be shrunken or otherwise properly secured upon' the outer face of the rim as shown in` Figs. v15y and16. By means of thisor other suitable reinforcement therotor may safelv be run at verv'high speedwexceeding the safety liinit of cast metalalone. i A i They spokesk2 are preferably'. madel in the form pf lthin blades Vand set at suitable anv lies across and closes the outer end to many modiications gles, (as shown in Figs. 1, 6, 15 and 16), to serve as fan blades for forcing a current of cooling air through kthe engine. Y

The cylinder I opens inwardly into the crank case and is closed at its outer or rim end, the closure having an aperture through which the charges of gas may be drawn, ignited and exhausted, said aperture being of much less area than the area of the cylinder.

The construction of this apertured closure, at present most preferred is shown in Figs. 1, 2, 8, 9 and 10, in which a plate or shoe J snugly fitted into a notch or recess j formed in or across the peripheral face of the rotor f the cylinder. This plate or shoe is formed truly concentric and, preferably, is set with its face slightly above the face of the rotor rim and it is held in place by screws y" or other suitable means. It is apertured as at j? in the form of a narrow slot extending lengthwise across the cylinder and circumferentially of the rim, or in the direction of movement ofy the rotor.

" the area of stator surface exposed to the pressure of the gas charge in the cylinder and thereby lessen the force which tends to push the rotor away from the stator surface and impair the perfection of closure around the cylinder at this point.

The shoe, in traversing the stator may be said to float along over a lilm of lubricating oil. 1n order to still further perfect the closure around the opening jg means are employed to form lines or ridges of the oil around said' opening such the inner bore of 'as the V-shaped grooves jt of Figs. 8, 9 and 10, in which the outer walls or those farthest away from the opening are preferably vertical and tend to catch and collect the oil in ridges which ride in almost frictionless contact with the inner surface of the stator and act as barriers against the escape of the gas from the cylinders. This feature is subject of form, a desirable one of whichis shown in Fig. 11 where the grooves around Vthe opening jghave vertical walls on both sides and are fitted with thin flat metal rings js which are forced outwardly by centrifugal action into contact with the inner surface of the stator from which they will scrape 0E and gather lubricant and hold it in the form of ridges or dams for the purpose set forth.

.Instead of blocking or clnsinothe outer Its ends ja are inj `clined outwardly to extend the periods of end of the cylinder with a detachable shoe like J, just described, this might be accomplished in many other ways such as the head z', cast integrally with the cylinder and suitably slotted as shown bv Figs. 12, 13 and 14: and at the lower side of Fig. 16 or, if a tire band H2 is used, it might be slotted or otherwise perforated at the cylinder points and serve to form the desired closure as shown by Fig. and the upper side of Fig. 16.

The crank shaft L of this engine is mounted, as before stated in its own bearing o and c2 independently of the rotor bearings. lt is, of course, provided with a single or a plurality of cranks Z corresponding to the number of cylinders in the engine; in this case two, and they as Well as their cylinders, etc., are located on offset centers along the axis as shown in Figs. 2, 6, 8, 10, 11 and 16, for purposes well understood. For this reason the cylinder apertures jg are located off centers, right and left, of their cylinders in order that they may register with the centrally disposed inlet and outlet ports and the spark plug openings.

The pistons M are connected by pitmen N to these cranks and in order that these pistons may make two complete in-and-out reciprocations for each revolution of the rotor the'crank shaft revolves in a direction opposite to that of the rotor. This is accomplished by means of gears suitably mounted in the gear case E at the front of the stator l and grouped as shown in Figs. 2, 6 and 7; the wheel O, secured on the rotor, engaging a wide faced' pinion 0 mounted on a bearing pin 0 and meshing in a different plane with asimilar pinion p mounted on another bearing pin p and engaging another gear wheel P keyed to the shaft. The direction of rotation of each of these gears is shown in Fig. 7 where the rotor wheel O turns oppositely to the shaft wheel P.

Tt is desirable that the rotor should be fitted into the upper half of the stator with nice exactness and into the lower half with more clearance or freedom, because all of the pressures in the cylinder occur while it is traveling the upper half and for the further reasons that the clearance at the bottom will allow of some settlement of the rotor, through wear of its bearings and perhaps also through spring of the parts caused at moments of greatest pressure in the cylinder, without causing undue pressure and consequent friction of the rotor in the lower half of the stator. Tnk order to accomplish this the stator is first bored to the exactness desired for its upper part and then the axis of the boring tool is lowered and the lower part of the stator is re-bored to the desired clearance which, for example, in practice,

'should be about one-half of one hundredth of an inch greater than in the upper half of the stator, an extremely small amount, yet

sulicient for the purpose oi lessening the chances of binding at this point. This feature is illustrated in Figs. l, 2 and 4. In Figs. 1 and 2 the space shown at S on the lower sides between shoes J and bore kof the stator indicates this clearance on a greatly exaggerated scale even for natural size, while in Fig. 4 the light line S at lower side of figure indicates the truly concentric bore and the heavier line S2 below it the rebored surface of the stator.

In operation, when the cylinder is at eitherl its highest or lowest points on a vertical line through the axis the crank is on the same side of the axis as the cylinder and the piston is at the extreme of its outward throw, and when the cylinder is on either of its horizontal points, the crank is on t-he farther side of the axis from the cylinder and the piston at the extreme of its inward throw. Referring to these tour cardinal points by numbers on Fig. 1, beginning with 1l at the bottom, 12 at the left or inlet side, 13, at the top or ignition quarter, and 14 on the right or exhaust side, it will be noted that vthe exhaust port a2 terminates at the very lowest point 11, of the stator at which point the piston has completed its outward scavenging throw. The initial end a of the inlet port a, Figs. 3 and 4, is spaced tar enough away from the exhaust port to prevent the cylinder opening jg from communieating with both of the ports at the same time, while the other end 41 of the inlet port is carried above and beyond the horizontal point 12 in order to extend the intake period as much as possible, the position of the cylinder when the intake ceases being shown by dotted lines I. The crank at this time has passed beyond dead center of alinement with the cylinder and through that portion of its arc where it imparts no material outward movement to the piston but its continued rotation moves the piston outwardly with great rapidity to compress the charge until the piston reaches its extreme outward throw as the cylinder arrives at the upper cardinal point 13. It will be noted that the initial end of the exhaust port is advanced above the horizontal cardinal point 14 and opens communication with the cylinder when it is at the position indicated by dotted lines I3 which is considerably in advance of point 14 where the cylinder and crank come into alinement and the piston is farthest retracted. However, at the time when the cylinder opens communication with the exhaust port, the crank will be passing into that part of its arc near the dead center'where it is least receptive of propelling force from the piston and the advantage of early opening of the exhaust more than compensates for any slight loss ot power caused thereby.

`It should be understood that when the engine is running at high speeds its mechanical elements move with immense lrapidity, much more rapidly, in fact, than the inertia of the gases' at either inlet or exhaust ports will admit of their responding to in full volume, normally and of their own volition, it in any way retarded or restricted and for this reason the ports are so proportioned and disposed as to extend the periods of'their communication with the cylinder toy the utmost limits.

This is also true with the ignition and resultant expansion of the charge. While these actions seem very rapid they must, in order to develop the highest efficiency of the charge at highspeeds of the engine, be given the greatest possible amount of time especially for .the complete spread of combustion throughout the charge. To eifect this result the engine is provided with a spark plug T set at a considerable distance in advance of upper point 14 so that ignition of the charge may be edected when the cylinder reaches the position indicated by dotted lines I2 with the advanced end of its slot jg communicating with said spark plug. At this position of the cylinder the crank and pitman are not yet in straight alinement and the piston has not yet completed its outward, compression throw, but the speed of the engine parts is so great that they reach the positions of complete outward throw, at upper point 13, about the time complete combustion has spread throughout the entire charge. By this means the maximum expansive force of the exploded charge is ready to act upon the piston at the very beginning of its inward stroke. However, such extreme advanced ignition is only suitable for the high speeds of the engine in which the great momentum of the rotor carries it past the slight back pressure7 points but the ignition moment may be retarded at this spark plug T by any suitable spark time regulating device now in common use.

To avoid the danger of back firing and reversal of the engine when it is being started or run at low speeds, it is preferable to use an additional spark plug T located on or near the cardinal point 13 on the vertical center line of the cylinder, etc., at the upper point 13 as shown in Figs. 1 and 4. Electric current may be continuously supplied to this spark plug T for all speeds but it should not be supplied to the advance plug T except for high speed work. For conservation of electric power, circuit switches either automatic or manually operable should be employed to cut outv the starting plug T and cut in the plug T upon the attainment of a predetermined speed and to reverse these conditions when the engine runs slower than said speed or is stopped.

It is understood that the rotor shall act as a fan to force air drafts through the. engine,

and while it is preferred to fashion the integral spokes to form fan blades, as described, it is not intended to confine the invention to this precise construction but to include any suitable construction that will eect the desired end, such for instance, as attaching to the rotor, in any suitable manner, separately formed fan blades of any suitable shape or material.

The space between the lower ends of the exhaust and inlet ports must not be less than the length of the cylinder opening 3'2 but it is desirable in some instances to make it somewhat greater than'the length of said opening in which event the retracting pisv; ton will create a partlal vacuum the inlet port, a condition that isV desirable in some cases.

Having fully described my invention, what I claim and desire to secure by Letters Patent iszl. In a rotary gas engine, the combination of an inclosing stator-member; a rotor-member within the latter; a crank-shaft journaled in said stator-member; a radially disposed cylinder in said rotor-member; and a piston within said cylinder suitably connected with said shaft; said rotor-member being mounted upon said stator member independently of said shaft.

2. In a rotary gas engine, the combination of an inclo'sing stator-member; a rotor member within the latter; a crank-shaft journaled in said stator-member; a radially disposed cylinder in said rotor-member; and a piston within said cylinder suitably connected with said shaft; said stator-member being provided with a journal upon which said rotor-member is mounted.

3. In a rotary gas engine, the combination with a stator member having an interior slightly elliptical bearing surface, intake in the cylinder before coming into registration with and exhaust ports formed in said stator member, a rotor member formed with an outer cylindrical bearing surface adapted to cooperate with the interior bearing surface of the stator, a cylinder carried by said r0- tor, a piston within said cylinder, a crank shaft journaled in the stator member and suitable connections between the piston and the crank shaft.

1l. In a rotary gas engine, the combination with a stator member having an interior slightly elliptical bearing surface, intake and outlet ports formed in said stator, a rotor member having a cylindrical bearing surface mounted within said stator member and cooperating with the interior surface of the stator, the said rotor having its axis eccentrically located with reference to the center of said elliptical surface, a cylinder carried by said rotor member, a piston within said cylinder, a crank shaft carried by the stator, and operative connections between the piston and the crank shaft.

5. In a rotary gas engine, the combination of an engine stator member, comprising a casing having alined bearings, annular proj ections upon the casing extending inwardly, said projections being axially disposed with respect to the said bearings, a rotor member, comprising a central crank casing and radially disposed cylinder casings, said rotor member having alined bearing portions which coperate with the annular projections upon the stator member, to rotatably support the rotor.

In testimony whereof I have signed my.I name to this specification in the presence of two subscribing Witnesses.

PI-IELPS M. FREER.

Witnesses:

DEBORAH L. JONES, B. JONES.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents, Washington, D. G. 

